I’ve never felt the significance of that. I understand the significance, but I can’t feel just how earthshaking that must have been to anyone who was more than, let’s say, 20, at the time: people old enough to have an understanding of how things are, who lived in a world where people didn’t leave the planet except in flights of fancy.

Fifty years ago I was four years old, the oldest of three kids living in Birmingham, Alabama. I knew nothing about Yuri Gagarin or the Soviet Union, or the Redstone Arsenal just 50 miles away in Huntsville, where Wernher von Braun and his team were developing the heavy lift rocket that would make the moon landing possible. (You had three TV stations to choose from (not counting educational television), if you were lucky, telephones had dials and many lived in booths, cars as well as fish had fins, the prestigious post-season college basketball tournament was the NIT, and there were only 16 big league baseball teams.)

Today I’m 50 years older; I live outside of Houston, and I work in the American space program, for the public affairs office at the Johnson Space Center. Today I interviewed the astronaut who will command the last flight of the space shuttle, which is planned for this summer. Just a regular work day.

If I can’t imagine the amazement that people felt 50 years ago, can I imagine what the world would be like if we had never left the planet, even for brief periods? Would we have had any incentive to create semiconductors (and then faster semiconductors), to miniaturize computers, to put geostationary satellites in orbit? Would we still have put a powerful telescope in orbit that would revolutionize astronomy, or have figured out a way to fix it once it got there? Would Gene Roddenberry and George Lucas still have been inspired to create other worlds that in some ways have come true in ours? Would the Colt .45s still be in the National League?

1965, first National League game at the Astrodome (Phillies 2, Astros 0; oh well). Less than two months later Houston became the Mission Control Center for U.S. manned spaceflight on Gemini 4, the flight that featured the first American spacewalk. Then we went to the moon—for that, I was old enough to feel the amazement. Then we stopped going to the moon, or anywhere else in space.

1981, first space shuttle flight. It was amazing to watch that launch—it was so much different than other rockets we’d seen—and I remember being very skeptical about that thing making a soft landing when it came down. Then it started pulling off missions that the Mercury 7 only ever dreamed about: retrieving and repairing satellites, supporting all kinds of advanced and (to the layman) esoteric science research, staying in space for weeks at a time—weeks, I tell you! Then docking to a Russian space station, then building one of our very own in a successful partnership with most of the Western world. Now that’s amazing!

2011: the 50th anniversary of Gagarin’s flight, the 30th anniversary of the first shuttle mission, and NASA announces where Enterprise, Discovery, Atlantis and Endeavour will spend their retirement.